<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>
    var socket;
    if(window.WebSocket){
        socket = new WebSocket("ws://localhost:55555/hello");
        // ev 收到服务器端回送的消息
        socket.onmessage = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = rt.value + "\n" + ev.data;
        };

        socket.onopen = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = "连接开启了";
        };
        socket.onclose = function (ev) {
            var rt = document.getElementById("responseText");
            rt.value = rt.value + "\n" + "连接关闭了";
        };
    }else {
        alert("当前浏览器不支持websocket");
    }

    // 发送消息到服务器
    function send(message) {
        if(!window.socket){
            return;
        }
        if(socket.readyState === WebSocket.OPEN){
            socket.send(message);
        }else {
            alert("服务器还没启动")
        }

    }
</script>
    <form onsubmit="return false">
        <textarea name="message" style="height: 300px; width: 300px"></textarea>
        <input type="button" value="发生消息" onclick="send(this.form.message.value)">

        <textarea id="responseText" style="height: 300px; width: 300px"></textarea>
        <input type="button" value="清空内容" onclick="document.getElementById('responseText').value= ''">
    </form>
</body>
</html>